Big dams, scarce water, thirsty India, uncertain monsoon

India’s largest major reservoirs by volume. (from top left to bottom right)) Indira Sagar (MP, 9.745 bcm), Srisailam (AP, 8.288 bcm), Nagarjuna Sagar (AP, 6.841 bcm), Gandhi Sagar (MP, 6.827 bcm), Ukai (GUJ, 6.615 bcm) and Bhakra (HP, 6.229 bcm).

Why did India’s Ministry of Water Resources not start rationing water use at the beginning of 2013? Data on the water levels of the 84 major reservoirs in the country (kept by the Central Water Commission) show an alarming rate of withdrawal over the period January to March 2013.

Over seven weeks, these reservoirs disgorged 20.525 billion cubic metres (BCM) of water – for industrial, commercial, residential and irrigation purposes. By 14 March 2013, the combined water stock in these 84 major reservoirs was 57.355 BCM – on 24 January 2013 that total had been 77.869 BCM. At this rate of water use, by 09 May 2013 – seven weeks hence – there will be a perilous 36.8 BCM in the major reservoirs, and with the possible first onset of the 2013 south-west monsoon still a month away.

The major reservoirs that have disgorged the most water during this period are: Srisailam (Andhra Pradesh) 2.353 bcm; Hirakud (Orissa) 1.808 bcm; Indira Sagar (Madhya Pradesh) 1.652 bcm; Nagarjuna Sagar (Andhra Pradesh) 1.082 bcm; Ukai (Gujarat) 0.976 bcm; Pong (Himachal Pradesh) 0.913 bcm; Gandhi Sagar (Madhya Pradesh) 0.899 bcm; Rihand (Uttar Pradesh) 0.734 bcm; Bhakra (Himachal Pradesh) 0.668 bcm and Koyna (Maharashtra) 0.598 bcm.